I haven't really cared to learn the "soul trapping" mechanic in Skyrim. I know that captured souls are used to recharge magic weapons but because I rarely use those (are magic weapons even essential?) I haven't put much weight to learning the mechanic. There are already so many different spells and mechanics in the game that everything new and distinct feels overwhelming.

I've considered using Spell Eraser utility.

http://www.nexusmods.com/skyrim/mods/18096/?

It's useful if you don't have any weapons to capture souls for you. Obviously if you use enchanted weapons, you'll be needing that to recharge them. Enchanted weapons aren't a necessity though.

Soul trap was Originally essential if you wanted to do enchanting,

However, Dawnguard literally made Soul Trap obsolete

I find using the soul trap spell awkward in combat.

I almost always eventually find some weapon with a soul trap enchantment. It is much more fluid in combat.

Another option is the conjured weapons spells. There is a conjuration perk that causes all conjured weapons to effect soul trap whenever you kill something.

the soul trap spell is only worth it to characters that don't use weapons.

otherwise its VERY useless. I prefer soul trap on a bow. I can fill even black soul gems pretty quick this way.

It's important if you use enchanting and want to level it. If you use it only for weapon recharging especially vanilla weapon, loot soul gem will be enough but if you use staff you may need to use soul trap.